Globe-holder for arc-lamps.



No. 697,757. Patented Apr. 5, I902.

G. E. STEVENS.

GLOBE HOLDER FOR ABC LAMPS.

(Application filed Sept. 15, 1899.}

(No Model.)

Inventor.- Geprge ESL-evens] by MVMM.

Mtnesses.

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UNITED STATES PATENT GFFICE.

GEORGE E. STEVENS, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEWV YORK.

GLOBE-HOLDER FOR ARC-LAMPS.

SPECIFICATION forming part of Letters Patent No. 697,757, dated April 15,1902. Application filed September 15, 1899. Serial No. 730,560. (No model.)

To ctZZ whom it may concern:

Be it known that I, GEORGE E. Srn'vnns, a citizen of the United States, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Globe-Holders for Arc-Lamps,'. (Case No. 1,366,) of which the following is a specification.

The object of this invention is to provide an improved globe-holder for arc-lamps of simple construction capable of permitting a ready clamping and removal of the globe.

The invention is particularly designed for use in connection with the inner globes or are inclosures employed in inclosed-aro lamps.

In carrying .out my invention I provide a holder for the negative carbon adapted to be readily inserted or removed from the yoke or other support on the lamp provided for it. I mount on this carbon-support a socket or plate to receive the lower neck of the globe and provide a fastening device capable of being shifted to overlap its edge and be adjusted toward or away from the axis of the globe. I preferably provide a plurality of these clamping devices symmetrically placed on the socket and pivoted so that when free they open outwardly and clear the neck of the globe, permitting it to be removed, but may be forced inwardly toward the globe-axis by a screw adjustment.

My invention comprises a globe-support and a pivoted fastening device mounted thereon and adapted to be adjusted by means below the flange of the globe to or from its axis.

My invention further comprises an improved insulating device especially useful in arc-lamps.

Other features of novelty more specific in character will be hereinafter definately indicated.

In the drawings, Figure 1 is a side elevation of a globe-holder embodying myimprovements. Fig. 2 is a sectional view of the same, the arc-inclosures being shown in dotted lines. Fig. 3 is a top plan view of a globeholder and its supporting-yoke. Fig. 4 is a modified form of supporting-yoke. Fig. 5 is a detail sectional view showing the improved bushing used on the yoke.

Referring to the drawings, 1 represents a support for the globe-holder, which is also a carbon-holder, being provided with a socket, as indicated in Figs. 2 and 3, to receive the negative electrode. In the wall of the support is provided a set-screw 2 for clamping the negative carbon.

3 representsa globe-support, preferably recessed on the upper face and provided with apacking-ring of soft fireproof material, such as asbestos. In the edge of this support are one or more clamping-fingers 4, mounted so as to be projected toward the axis of the globe 5. The globes commonly employed in inclosed-arc lamps are provided with a contracted neck at the bottom and have a slight outward curve or flare. The fingers 4 are mounted so that the tips may be forced inwardly toward the axis of the globe to clamp it in position and support it. In the design shown in the drawings I have shown three such fingers symmetrically placed on the support and pivoted in grooves or slots formed in its periphery, an adjusting-nut 6 screwing over the stem of the support and serving to force outwardly the lower ends of the fingers. It is, however, not absolutely essential that a plurality of such fingers be employed, since if the socket is provided with an undercut recess one finger might serve to lock the globe in position. Iprefer to pivot them so as to'rock freely, and the lower ends are made sufficiently heavy as to require no other force than gravity to throw the upper engaging tips outwardly when the screw 6 is lowered.

The supporting-stem of the globe-holder is mounted in a yoke 7 or other part of the lampframe. In the type shown in the drawings this yoke is supported from two side rods or tubes 8 8, employed on a standard type of lamp, in which tubes move the guide-rods for the outer globe, (not shown,) as they form no part of the present invention. It is desirable in this type of lamp to insulate the yoke from the tubes, and I provide for that purpose an improved bushing, the details of which are shown in section in Fig. 5. The opening through which the yoke is clamped to the tubes or other support is lined with insulating material, such as mica, (indicated at 9,)

and one or more thin metal tubes are inserted through the insulation and upset on the side, so as to overlap the edges of the hole. I preferably employ a plurality of these metal tubes, thereby permitting an easy spreading of the ends, and yet providing a substantial thickness of the metal lining. By this organization a solid end wall is provided at both sides of the opening, against which the metal parts which support it may abut without damage to the insulation, and the parts may be firmly screwed together without danger of injuring the insulation.

The stem or globe-holder support is removably connected with the yoke in order to permit the globe and its holder to be easily removed for the purpose of cleaning and trimming. I have shown two locking devices for the stem, that embodied in Figs. 1, 2, and 3 comprising a cylindrical socket open at one side, through which opening the stem can be inserted. The stem is provided with a peripheral groove 11, against which may be adjusted tangentially the tip of a set-screw 12. The form of the socket and the cooperative relation of the stem and set-screw 12 are clearly shown by the dotted lines in Fig.

An alternative form of yoke is shown in Fig. i. This comprises a cylindrical socket 13, formed in the yoke, and the latter is provided with two long saw-cuts 13 13", made longitudinally of the yoke, and two clamping-jaws are formed by sawing through one side of the yoke, as indicated at 14. The set-screw 15 permits the two jaws thus formed to be spread or contracted, so as to clamp the cylindrical stem of the globe-support.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. A globe-holder for an inclosed-arc lamp, comprising a recessed seat for the neck of the inner globe, a socket for the lower carbon below said seat, a stem detachably connected with a yoke connecting the side rods, a plurality of symmetrically-spaced pivoted clamps, and a nut threaded on the stem to adjust the clamps, said nut being below the plane of the globe-seat.

2. A supporting-yoke for a globe-holder split longitudinally of its axis to form two jaws, a cylindrical socket between the jaws for the stem of the globe-holder, and a setscrew to compress or spread the jaws.

3. An insulated metallic bushing comprising a metal tube threading an insulating-lining and having its ends upset over the edges of said lining.

4. An insulated metallic bushing comprising one or more thin metal tubes threading an insulated lining and upset at its ends over the edges of the lining.

In witness whereof I have hereunto set my hand this 11th day of September, 1899.

GEORGE E. STEVENS.

Witnesses:

DUGALD McKILLoP, JOHN McMANUs. 

